Improvement in screw-propellers



PATENT QFFICE.

JOHN OOOHRANE, OF WALL TOWNSHIP, NEW JERSEY.

IMPROVEM ENT IN SCREW-PROPELLERS Specific tion forming part of Letters Patent No. 116,414, dated June 27, 1871.

To all whom it may concern:

city and county of New York and State of New York, have invented a new and useful Improvement in the Construction of Screw-Propellers for Steam-Vessels; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawing and to the figures and letters marked thereon, in which Figure 1 is a front elevation of the propeller complete, and Fig. 2 a front elevation of one blade and its portion of the hub.

To enable others skilled in the art to make and use my invention, I will proceed to describe the manner in which I construct and combine the parts together.

I make the blade of any desirable form, and cast with it its proper portion of the hub, as shown in Fig. 2, in which A is the blade, and B a portion of the hub. At one edge of the hubpiece B I make a groove, 1), parallel to the axis of the propeller, and at the other edge a corresponding tongue, 0, and each segment of the hub being thus formed and fitted they are all put together as shown in Fig. 1, and secured in position by wrought-iron bands shrunk on the outer and inner ends of the hub, as shown by F F, Fig. 1. The propeller, thus constructed and com bined together, will be as durable and effective as if made of a single casting, while any of the parts that become broken may be renewed at comparatively less cost than that of the whole wheel.

I am aware that it has been essayed to con struct propellers by forming them in pieces, the segments of the hub having nortises and tenons cast thereon. I do not, therefore, claim the use of mortises and tenons; but

What I do claim as my invention, and desire to secure by Letters Patent, is-

The tongued and grooved hub joints, in. com bination with the hub-bands, substantially as de scribed.

JOHN GOOHRANE.

Witnesses:

STEPHEN S. GARRISON, HAL. ALLAIRE. 

